Peptic Ulcers (Gastric Ulcers): A peptic ulcer is a sore in the lining of the stomach or duodenum. They usually appear as single, round cavities with smooth borders that penetrate the submucosa.  Most people with peptic ulcer disease are infected with bacterium Helicobacter pylori, and elimination of the infection promotes rapid healing of the ulcer. 
[Figures 1, 2,3] 

Cholelithiasis (Gallstones): Gallstones are caused by precipitation of substances within bile, mainly cholesterol and bilirubin. About 75% of gallstones are composed primarily of cholesterol. Also, 25% are black or brown pigment stones consisting of calcium salts with bilirubin. Gallstones are formed when bile contains a high concentration of a component such as cholesterol or there is a shortage of bile salts. [Figures 4,5,6]

Figure 1                                        

Figure 3

Figure 4